Evaluation of Diffuse Bone Marrow Infiltration Pattern in Monoclonal Plasma Cell Diseases by Quantitative Whole-body Magnetic Resonance Imaging.

Rationale and Objectives To analyze diffuse infiltration pattern in monoclonal plasma cell diseases by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) and quantitative chemical-shift encoded MRI. Materials and Methods Ninety-nine patients with monoclonal plasma cell diseases and 15 healthy control subjects were retrospectively analyzed. All patients underwent whole-body MRI (including DWIBS and mDIXON Quant) and were divided into three groups: monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM). Apparent diffusion coefficient (ADC), fat fraction (FF), and T2* values for each group were calculated then analyzed by one-way ANOVA and receiver operating characteristic curve. Correlations of ADC, FF, and T2* with clinical indices were analyzed with Spearman correlation test. Results The ADC and T2* values of MM were significantly higher than those of the healthy control, MGUS and SMM (ADC: p = 0.003, p = 0.003, and p = 0.042; T2*: all with p Conclusion ADC, FF, and T2* were significantly correlated with clinical indices related to monoclonal plasma cell diseases. MM with the diffuse infiltration pattern can be distinguished more objectively from MGUS and SMM by quantitative functional MRI parameters.